Non-shearing solderless electrical connector

ABSTRACT

In a solderless electrical connector of the type comprising relatively rotatable male and female jaws having respective mounting tails adapted to be secured against a support and alignable bores adapted to receive the bared end of a conductor which is securely clamped between the jaws when they are rotated to a closed position, there is disclosed the improvements wherein the bore in the male jaw is slightly larger than the bore in the female jaw to permit the conductor to &#39;&#39;&#39;&#39;bird-cage&#39;&#39;&#39;&#39; when the jaws are rotated to the closed position, wherein a chamfer or countersink is added to the entrance of the bore in the female jaw for ease of insertion of the conductor thereinto, wherein the aperture in the tail of the female jaw is drilled at a slight angle therethrough, and wherein the tail of the male jaw is slightly concave to increase the area of contact between such tail and the adjacent support in the closed position of the jaws.

United States Patent Shugarman et al.

[ NON-SHEARING SOLDERLESS ELECTRICAL CONNECTOR [75] Inventors: Alvin E.Shugarman; Lowell E.

Linder, both of Santa Ana, Calif {73] Assignee: Electro-ClampCorporation, Beverly Hills, Calif.

[22] Filed: Apr. 26, I973 [2i] Appl. No.: 354,645

[451 May 13, 1975 Primary Examiner-Joseph H. McGlynn Attorney, Agent, orFirm-Hume, Clement, Brinks Willian, Olds & Cook, Ltd

[57] ABSTRACT In a solderless electrical connector of the typecomprising relatively rotatable male and female jaws having respectivemounting tails adapted to be secured against a support and alignablebores adapted to receive the bared end of a conductor which is securelyclamped between the jaws when they are rotated to a closed position,there is disclosed the improvements wherein the bore in the male jaw isslightly larger than the bore in the female jaw to permit the conductorto bird-cage" when the jaws are rotated to the closed position, whereina chamfer or countersink is added to the entrance of the bore in thefemale jaw for ease of insertion of the conductor thereinto, wherein theaperture in the tail of the female jaw is drilled at a slight angletherethrough, and wherein the tail of the male jaw is slightly concaveto increase the area of contact between such tail and the adjacentsupport in the closed position of the jaws.

19 Claims, 4 Drawing Figures NON-SHEARING SOLDERLESS ELECTRICALCONNECTOR BACKGROUND OF THE INVENTION 1. Field of the Invention Thepresent invention relates to non-shearing solderless electricalconnectors and. more particularly, to an improved connector of therotatable jaw, clamping type.

2. Description of the Prior Art Solderless electrical connectors of thetype having relatively rotatable jaws with alignable bores thereinadapted to receive the bared end of a conductor which is securelyclamped between the jaws when they are to tated to a closed position arewell known in the art. Such connectors are disclosed in the followingUS. patents: Tracy, US. Pat. No. 2,752,583; Shuck et al, US. Pat. No.3,118,720; Lawlor, US. Pat. No. 3,138,422; Tracy, US Pat. No. 3,169,818;Lawlor et al, US. Pat. No. 3,351,889; Lawlor, U.S. Pat. No. 3,406,372,Beaudion, US. Pat. No. 3,437,979; Lawlor, US. Pat. No. 3,477,060; andLaw1or,U.S. Pat. No. 3,579,177.

These patents disclose solderless electrical connectors comprising, ingeneral, male and female jaws coupled for relative pivotal movementbetween an open position in which the bared end of a conductor can befreely inserted through aligned bores in the jaws and a closed positionin which the conductor is securely clamped between the jaws therebyestablishing a good electrical and mechanical connection. Movement ofthe jaws from the open to the closed position is controlled by a stud orbolt or other fastening means which is utilized to secure the tails ofthe male and female jaws to a suitable support.

In solderless electrical connectors of this type, a significant objectis to permit clamping of the conductor between the relatively rotatablejaws without any shearing action so as not to weaken the conductor bythe clamping action of the jaws. For similar reasons, it is also anobject to secure the tails of the jaws to the support without bendingthe tails, If either the conduc tor is damaged or the tails are bent,the electrical con ductivity from the conductor to the support throughthe connector is diminished. Shearing of the conductor decreasesconductivity by decreasing the area thereof and bending of the tailsdecreases conductivity by decreasing the area of electrical contactbetween the tails and the support. Furthermore, shearing of theconductor decreases the strength thereof thereby decreasing the abilityof the connector to withstand pull-out of the conductor.

Other objects of this type of solderless electrical con nector are topermit ease of insertion of the conductor thereinto and to permit easeof assembly to the support. With respect to the former object, the endof the conductor has a tendency to expand when it is cut and stripped,making insertion difficult. With respect to the latter object, drillingof the holes in the tails of the jaws to conform to the standards of theNational Electrical Manufacturers Association (NEMA) makes it extremelydifficult to pass a bolt through the holes because of the angularmisalignment of the tails.

SUMMARY OF THE INVENTION According to the present invention, there isprovided an improved non shearing solderless electrical connector whichis effective in satisfying the objectives discussed above to a degreeunobtainable heretofore. With the present connector, the conductor ispermitted to deform as the jaws are rotated to the closed positionwithout any shearing action and without decreasing electricalconductivity or the strength of the conductor. in addition. the mannerin which the conductor deforms significantly increases the forcerequired to separate the conductor and the connector. Furthermore, withthe present design, the area of contact between the connector and thesupport it is mounted on is maximized so as not to decrease electricalconductivity through the connector. Still further, with the presentconnector, it is easier to insert the conductor into the opening in thefemale jaw than has been possible here tofore and it is also easier topass a stud or bolt through the apertures in the male and female jawsfor connection to the support.

Briefly, the present non-shearing solderless electrical connector of therotatable jaw, clamping type, compris ing male and female jaws havingrespective mounting tails adapted to be secured against a support andalignable bores adapted to receive the barcd end of a concluctor whichis securely clamped between the jaws when they are rotated to a closedposition, is improved in several significant respects. The bore in themale jaw is slightly larger than the bore in the female jaw and has achamfer at the opposite ends thereof to permit the conductor tobird-cage" or spread when the jaws are rotated to the closed positionthereby preventing shearing and increasing the required pull-out force.A chamfer or countersink is added to the entrance of the bore in thefemale jaw for ease ofinsertion of the conductor thereinto. The aperturein the tail of the female jaw is drilled at a slight angle to a linenormal to the plane thereof to allow a stud or bolt to pass more easilythrough the apertures in the male and female jaw tails. Due to thetendency of all materials to bend when a force is applied thereto, thetail of the male jaw is slightly concave to increase the contact areabetween such tail and the support It is therefore an object of thepresent invention to provide a non-shearing solderless electricalconnector.

It is a further object of the present invention to provide an improvedsolderless electrical connector of the rotatable jaw, clamping type.

It is a still further object of the present invention to provide asolderless electrical connector of the rotatable jaw, clamping typewhich permits a conductor to bird-cage" when the jaws are rotated to theclosed position.

It is another object of the present invention to provide a solderlesselectrical connector of the rotatable jaw, clamping type wherein achamfer is added to the entrance of the bore in the female jaw for easeof insertion of the conductor thereinto.

It is still another object of the present invention to provide asolderless electrical connector of the rotatable jaw, clamping typewherein the aperture in the tail of the female jaw is offset from a linenormal thereto for ease of insertion of a stud or bolt therethrough.

Another object of the present invention is the provision of a solderlesselectrical connector of the rotatable jaw, clamping type wherein thetail of the male jaw is slightly concave.

Still other objects, features, and attendant advantages of the presentinvention will become apparent to those skilled in the art from areading of the following detailed description of the preferredembodiment constructed in accordance therewith, taken in conjunctionwith the accompanying drawings wherein like numerals designate likeparts in the several figures and wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of asolderless electrical connector constructed in accordance with theteachings of the present invention, with a conductor clamped therein;

FIG. 2 is a medial longitudinal section view thereof;

FIG. 3 is a medial longitudinal sectional view thereof in an openposition ready to receive the bared end of a conductor, and

FIG. 4 is a longitudinal sectional view taken along the line 44 in FIG.2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,there is shown, as an example of one form in which the present inventionmay be embodied, a solderless electrical connector, generally designated10, comprising, in general, male and female jaws A and B, respectively,coupled for relative pivotal movement between an open position, seen inFIG. 3, in which a conductor C can be freely inserted into jaws A and B,and a closed position, seen in FIGS. 1 and 2, in which conductor C issecurely clamped be tween jaws A and B and connected thereby to asuitable support D. Connection to support D is achieved by a suitablefastener, such as a stud or bolt E, as will be explained more fullyhereinafter.

Male jaw A comprises a cylindrical head or knuckle 11 formed integrallyon one end of a tail 12 which is adapted to be mounted against supportD, tail l2 having an aperture 13 through which bolt E can be extendedthrough and into support D. An offset neck 14 joins head 11 to tail 12,thus positioning head 11 above the plane of tail 12. The back of neck 14is generally normal to the plane of tail 12 whereas the front of head 11protrudes forwardly from neck 14, overhanging a transverse recess 15.Tail 12 is slightly concave so that only the opposite ends thereofcontact support D in the open position of jaws A and B, as seen in FIG.3.

Jaw A has a bore 16 which extends diametrically through the center ofhead 11 for reception of conductor C. Bore 16 is inclined downwardly andforwardly with reference to the plane of tail 12 at an angle which issubstantially equal to the angle between the tails of jaws A and B whenconnector is in the open position, seen in FIG. 3. This angle may varyfrom approximately 12 to approximately depending upon the size ofconductor C. In other words, as the diameter of conductor C increases.the angle of bore 16 decreases.

A cutter of approximately the same diameter of bore 16 through head 12may be used to chamfer or flare the respective end portions of bore 16,at 17 and 18, to eliminate a sharp edge which would tend to shearconnector 10 as jaws A and B are rotated to the closed position. Theupper half of bore 16 is chamfered, at 17, at the front of head 11whereas the lower half of bore 16 is chamfered, at 18, at the back ofhead 11. Furthermore, chamfers 17 and 18 should be rounded so as tocompletely eliminate any possibility of fracturing or cutting conductorC. This may be accomplished by oscillating the cutter during thechamfering operation.

Female jaw B comprises a C-shaped head or yoke 20 formed integrally onone end of a planar tail 21 which is adapted to contact tail 12 ofjaw Ain the closed posi tion. In the open position, tail 21 only contactstail 12 adjacent its intersection with neck 14 due to the concavity oftail l2. Yoke 20 defl. 1 a transverse cylindrical socket 23 in whichhead 11 ofjaw A is loosely fitted for tilting movement of jaw B betweenthe open position shown in FIG. 3 and the closed position shown in FIGS.1 and 2. Yoke 20 has the general form of a U- channel, modified by are-entrant lip 24 which extends beneath head 11 into recess 15 so as toretain head 11 captive within yoke 20. Recess 15 is positioned relativeto lip 24 so that the two are in contact when jaw B is in its openposition.

Tail 12 has an aperture 22 therein through which bolt E can be extendedthrough and into aperture 13 in tall 12 and support D. According to thepresent invention, aperture 22 in tail 21 is positioned at a slightangle relative to a line normal to the plane of tail 21, the angle beingapproximately one-half of the angle between tails 12 and 21 whenconnector 10 is in the open position.

Yoke 20 is provided with diametrically opposed cylindrical bores 25 and26 aligned on a common diameter of yoke 20, generally parallel to tail21, so as to be alignable with bore 16 in head 11 of jaw A when jaw B isin its open position, seen in FIG. 3. Bore 25 is positioned in the sideof yoke 20 which terminates in lip 24 whereas bore 26 is positioned inthe side of yoke 20 connected to tail 21. When connector 10 is open,bores 16, 25, and 26 are aligned so that conductor C can be freelypassed thereinto. Yoke 20 is also provided with a conical chamfer orcountersink 27 at the entrance to bore 25. Furthermore, the diameter ofbore 16 is slightly larger than that of bores 25 and 26.

OPERATION The basic operation of connector 10 is similar to that of manyof the connectors of the before-mentioned US. patents. In the openposition ofjaw B, seen in FIG. 3, bores 16, 25, and 26 are aligned,ready to receive the bared end of conductor C. At this time, lip 24, atthe end of yoke 20, extends into recess 15 and into engage ment withneck 14 thereby limiting the movement of jaw B beyond the open position.

Because of chamfer 27 at the entrance to bore 25 in yoke 20 of femalejaw B, it will be relatively easy to insert conductor C into bore 25,even with the tendency of the end of conductor C to bird-cage" orseparate when it is cut and stripped. The provision of chamfer 27 alsoreduces the tendency for the previous sharp edge to cut into and shearconductor C in the presence of vibration thereof.

After insertion of conductor C into the aligned bores i6, 25, and 26 injaws A and B, jaw B may be closed upon jaw A by application of adownward force on tail 21. This may be achieved by passing a stud orbolt E through apertures 22 and 13 in tails 2] and 12, respectively, andinto support D. With aperture 22 drilled at the previously describedangle relative to the plane of tail 21, it is much easier to insert boltE through aperture 22 and then into aperture 13.

Tightening of bolt E into support D moves tail 21 towards and intocontact with tail 12. However, due to the tendency of all materials tobend when any force is applied thereto, it has been found, in practice,that tail 21 bends downwardly and tail l2 bends upwardly.

While the downward bending of tail 21 does not pres ent a problem, theupward bending of tail 12 limits the contact area between tail l2 andsupport D, thereby decreasing the electrical conductivity. By makingtail 12 slightly concave so that tail 21 and 12 meet just before theyield point of the material, not only is a good surface contactguaranteed between tail 12 and support D, but a spring force isestablished to maintain bolt E tight.

As known in the art, with movement of tail 21 into contact with tail 12,bores 16 and 25 become angularly misaligned so as to distort the baredend of conductor C, as seen in FIG. 2. This distortion of conductor Csecurely grips the bared end thereof within connector 10, preventing theremoval thereof. However, in the prior art, with the diameters of bores16, 25, and 26 being equal and just slightly greater than the diameterofconductor C, this gripping action tends to put conductor C in directshear, leaving almost no area for conductor C to deform into. Accordingto the present invention, this problem is overcome by enlarging bores16, 25, and 26 sufficiently to allow conductor C to become ellipticalwhen it is clamped. The diameter of bore 16 in male jaw A is slightlylarger than the diameters of bores 25 and 26 in female jaw B to allowthe strands of conductor C to bird-cage" or expand into this largerarea, as seen in FIG. 4.

The difference in the diameters of bores 16, 25, and 26 and conductor Cwill vary as a function of the diameter of conductor C. In other words,the increase in the diameters of bores 16, 25, and 26 over the diameterof conductor C should be such that the individual strands of conductor Cexpand up against the walls of bore 16. If the diameter of bore 16 wastoo large compared to the diameter of conductor C, contact between theindividual strands of conductor C and the wall of bore 16 would bedecreased, thereby decreasing conductivity through connector 10. Sincedifferent sizes of conductor C have a different ability to deform, thepercentage increase of bores 16, 25, and 26 over the diameter ofconductor C is a function of the size of conductor C. The smaller sizesof conductor C, which may have as few as seven individual strands ofwire, have been found to readily deform and the diameter of bore 16 maybe approximately 12% larger than the diameter of conductor C. As thesize of conductor C increases up to approximately 50 or 60 individualstrands of wire, there is less tendency to deform and bore 16 shouldhave a diameter only approximately 6% larger than the diameter ofconductor C. In either case, the increase in the diameter of bores 25and 26 over the diameter of conductor C is less than the increase in thediameter of bore 16. It has been found that ideally, the increase in thediameter of bores 25 and 26 is only 60% of the increase in the diameterof bore 16 over the diameter of conductor C. Tests have shown that thesedimensions substantially increase the force required to pull conductor Cout of connector when jaws A and B are in the closed position.

It can therefore be seen that in accordance with the present invention,there is provided an improved nonshearing solderless electricalconnector which is effective in satisfying the objectives of the priorart to a degree unobtainable heretofore. With connector 10, conductor Cis permitted to deform as jaws A and B are rotated to the closedposition without any shearing action and without decreasing electricalconductivity or the strength of conductor C. In addition, the manner inwhich conductor C deforms significantly increases the force required toseparate conductor C and connector 10. With the present design, the areaof contact between connector 10 and support D is maximized so as not todecrease electrical conductivity through connector 10. Furthermore, itis easier with connector 10 to insert conductor C into bore 25 in femalejaw B than has been possible heretofore and is also easier to pass boltE through apertures 13 and 22 in male and female jaws A and B,respectively, for connection to support D.

While the invention has been described withwespect to a preferredphysical embodiment constructed in accordance therewith, it will beapparent to those skilled in the art that various modifications andimprovements may be made without departing from the scope and spirit ofthe invention. Accordingly, it is to be understood that the invention isnot to be limited by the spe cific illustrative embodiment, but only bythe scope of the appended claims.

We claim:

1. In a solderless electrical connector of the rotatable jaw, clampingtype comprising male and female jaws having respective mounting tailsadapted to be secured against a support, said male jaw including atransverse cylindrical head joined to one end of said male jaw tail andhaving a bore which extends diametrically through the center of saidhead for receipt of a conductor, said female jaw including a C-shapedyoke joined to one end of said female jaw tail and defining a transversecylindrical socket which receives said head of said male jaw forrelative angular movement of said jaws between an open,conductonreceiving position and a closed, conductor-clamping position,said yoke having opposed cylindrical bores on a common diameter of saidyoke which are alignable with said bore in said male jaw in said openposition of said jaws, the improvement wherein the diameter of said borein said male jaw is throughout its length slightly larger than thediameter of said bore in said female jaw to permit said conductor toexpand when said jaws are rotated to said closed position.

2. In a solderless electrical connector according to claim 1, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open position and wherein said male jaw is sufficientlyflexible to permit said male jaw tail to bend to a substantially planarposition when said male and female jaw tails are secured against saidsupport.

3. In a solderless electrical connector according to claim 1, theimprovement wherein the end portions of said bore in said head arechamfered at the same diameter as said bore to eliminate a sharp edgefrom said end portions of said bore.

4. In a solderless electrical connector according to claim 3, theimprovement wherein the upper half of said bore in said head ischamfered at the front of said head and wherein the lower half of saidbore in said head is chamfered at the back of said head.

5. In a solderless electrical connector according to claim 1, theimprovement wherein the diameter of said bore in said head of said malejaw is larger than the diameter of the conductor to be inserted thereinby an amount lying within the range of 6 to 12%.

6. In a solderless electrical connector according to claim 5, theimprovement wherein the difference between the diameters of said bore insaid head and said conductor decreases as the diameter of said conductorincreases.

7. In a solderless electrical connector according to claim 5, theimprovement wherein the diameter of said bores in said yoke is largerthan the diameter of said conductor by an amount approximately equal to60% of the increase in the diameter of said bore in said head over thediameter of said conductor.

8. In a solderless electrical connector according to claim 1, whereinone side of said yoke is joined to said one end of said female jaw tail,the improvement wherein a chamfer or countersink is positioned at theouter end of said bore in the other side of said yoke to facilitateinsertion of said conductor thereinto.

9. In a solderless electrical connector according to claim 8, whereinsaid male and female jaw tails have alignable apertures therein adaptedto receive a fastener, the improvement wherein said aperture in saidfemale jaw tail is positioned at an angle relative to a line normal tothe plane of said tail which is approximately equal to one-half of theangle between said male and female jaw tails when said jaws are in saidopen position.

10. In a solderless electrical connector according to claim 9, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open position and wherein said rnale jaw issufficiently flexible to permit said male jaw tail to bend to asubstantially planar position when said male and female jaw tails aresecured against said support.

11. In a solderless electrical connector according to claim 1, whereinsaid male and female jaw tails have alignable apertures therein adaptedto receive a fastener, the improvement wherein said aperture in saidfemale jaw tail is positioned at an angle relative to a line normal tothe plane of said tail which is approximately equal to one-half of theangle between said male and female jaw tails when said jaws are in saidopen position.

12. In a solderless electrical connector according to claim 11, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open posi tion and wherein said male jaw issufficiently flexible to permit said male jaw tail to bend to asubstantially pla nar position when said male and female jaw tails aresecured against said support.

l3. In a solderless electrical connector of the rotatable jaw, clampingtype comprising male and female jaws having respective mounting tails,said male jaw including a transverse cylindrical head joined to one endof said male jaw tail and having a bore which extends through the centerof said head for receipt ofa conductor, said female jaw including aC-shaped yoke, one side of said yokde being joined to one end of saidfemale jaw tail, said yoke defining a transverse cylindrical socketwhich receives said head of said male jaw for relative angular movementof said jaws between an open, conductor-receiving position and a closed,con ductor-clamping position, said yoke having opposed cylindrical boreson a common diameter of said yoke which are alignable with said bore insaid male jaw in said open position of said jaws, the improvementwherein said aperture in said female jaw tail is positioned at an anglerelative to a line normal to the plane of said tail which isapproximately equal to one-half of the angle between said male andfemale jaw tails when said jaws are in said open position.

14. In a solderless electrical connector according to claim 13, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open position and wherein said male jaw is sufficientlyflexible to permit said male jaw tail to bend to a substantially planarposition when said male and female jaw tails are se cured against saidsupport.

15. In a solderless electrical connector according to claim 13, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open position and wherein said male jaw is sufficientlyflexible to permit said male jaw tail to bend to a substantially planarposition when said male and female jaw tails are secured against saidsupport,

16. In a solderless electrical connector of the rotatable jaw, clampingtype comprising male and female jaws having respective mounting tailswith alignable ap ertures therein adapted to receive a fastener and tobe secured against a support, said male jaw including a transversecylindrical head joined to one end of said male jaw tail by a neck andhaving a bore which extends diametrically through the center of saidhead for receipt of a conductor, said female jaw including a C- shapedyoke joined to one end of said female jaw tail and defining a transversecylindrical socket which receives said head of said male jaw forrelative angular movement of said jaws between an open,conductorreceiving position and a closed, conductor-clamping position,said yoke having diametrically opposed cylindrical bores on a commondiameter of said yoke which are alignable with said bore in said malejaw in said open position of said jaws, the improvement wherein saidaperture in said female jaw tail is positioned at an angle relative to aline normal to the plane of said tail.

17. In a solderless electrical connector according to claim 16, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open position wherein said male jaw is sufficientlyflexible to permit said male jaw tail to bend to a substantially planarposition when said male and female jaw tails are secured against saidsupport.

18. In a solderless electrical connector of the rotatable jaw, dampingtype comprising male and female jaws having respective mounting tailsadapted to be secured against a support, said male jaw including atransverse cylindrical head joined to one end of said male jaw tail by aneck and having a bore which extends diametrically through the center ofsaid head for receipt of a conductor, said female jaw including a Cshaped yoke joined to one end of said female jaw tail and defining atransverse cylindrical socket which receives said head of said male jawfor relative angular movement of said jaws between an open,conductorreceiving position and a closed, conductor-clamping position,said yoke having diametrically opposed cylindrical bores on a commondiameter of said yoke which are alignable with said bore in said malejaw in said open position of said jaws, the improvement wherein saidmale jaw tail is slightly concave when said jaws are in said openposition.

19. In a solderless electrical connector according to claim 18, theimprovement wherein said male jaw is sufficiently flexible to permitsaid male jaw tail to bend to a substantially planar position when saidmale and female jaw tails are secured against said support.

1. In a solderless electrical connector of the rotatable jaw, clampingtype comprising male and female jaws having respective mounting tailsadapted to be secured against a support, said male jaw including atransverse cylindrical head joined to one end of said male jaw tail andhaving a bore which extends diametrically through the center of saidhead for receipt of a conductor, said female jaw including a C-shapedyoke joined to one end of said female jaw tail and defining a transversecylindrical socket which receives said head of said male jaw forrelative angular movement of said jaws between an open,conductor-receiving position and a closed, conductor-clamping position,said yoke having opposed cylindrical bores on a common diameter of saidyoke which are alignable with said bore in said male jaw in said openposition of said jaws, the improvement wherein the diameter of said borein said male jaw is throughout its length slightly larger than thediameter of said bore in said female jaw to permit said conductor toexpand when said jaws are rotated to said closed position.
 2. In asolderless electrical connector according to claim 1, the improvementwherein said male jaw tail is slightly concave when said jaws are insaid open position and wherein said male jaw is sufficiently flexible topermit said male jaw tail to bend to a substantially planar positionwhen said male and female jaw tails are secured against said support. 3.In a solderless electrical connector according to claim 1, theimprovement wherein the end portions of said bore in said head arechamfered at the same diameter as said bore to eliminate a sharp edgefrom said end portions of said bore.
 4. In a solderless electricalconnector according to claim 3, the improvement wherein the upper halfof said bore in said head is chamfered at the front of said head andwherein the lower half of said bore in said head is chamfered at theback of said head.
 5. In a solderless electrical connector according toclaim 1, the improvement wherein the diameter of said bore in said headof said male jaw is larger than the diameter of the conductor to beinserted therein by an amount lying within the range of 6 to 12%.
 6. Ina solderless electrical connector according to claim 5, the improvementwherein the difference between the diameters of said bore in said headand said conductor decreases as the diameter of said conductorincreases.
 7. In a solderless electrical connector according to claim 5,the improvement wherein the diameter of said bores in said yoke islarger than the diameter of said conductor by an amount approximatelyequal to 60% of the increase in the diameter of said bore in said headover the diameter of said conductor.
 8. In a solderless electricalconnector according to claim 1, wherein one side of said yoke is joinedto said one end of said female jaw tail, the improvement wherein achamfer or countersink is positioned at the outer end of said bore inthe other side of said yoke to facilitate insertion of said conductorthereinto.
 9. In a solderless electrical connector according to claim 8,wherein said male and female jaw tails have alignable apertures thereinadapted to receive a fastener, the improvement wherein said aperture insaid female jaw tail is positioned at an angle relative to a line normalto the plane of said tail which is approximately equal to one-half ofthe angle between said male and female jaw tails when said jaws are insaid open position.
 10. In a solderless electrical connector accordingto claim 9, the improvement wherein said male jaw tail is slightlyconcave when said jaws are in said open position and wherein said malejaw is sufficiently flexible to permit said male jaw tail to bend to asubstantially planar position when said male and female jaw tails aresecured against said support.
 11. In a solderless electrical connectoraccording to claim 1, wherein said male and female jaw tails havealignable apertures therein adapted to receive a fastener, theimprovement wherein said aperture in said female jaw tail is positionedAt an angle relative to a line normal to the plane of said tail which isapproximately equal to one-half of the angle between said male andfemale jaw tails when said jaws are in said open position.
 12. In asolderless electrical connector according to claim 11, the improvementwherein said male jaw tail is slightly concave when said jaws are insaid open position and wherein said male jaw is sufficiently flexible topermit said male jaw tail to bend to a substantially planar positionwhen said male and female jaw tails are secured against said support.13. In a solderless electrical connector of the rotatable jaw, clampingtype comprising male and female jaws having respective mounting tails,said male jaw including a transverse cylindrical head joined to one endof said male jaw tail and having a bore which extends through the centerof said head for receipt of a conductor, said female jaw including aC-shaped yoke, one side of said yokde being joined to one end of saidfemale jaw tail, said yoke defining a transverse cylindrical socketwhich receives said head of said male jaw for relative angular movementof said jaws between an open, conductor-receiving position and a closed,conductor-clamping position, said yoke having opposed cylindrical boreson a common diameter of said yoke which are alignable with said bore insaid male jaw in said open position of said jaws, the improvementwherein said aperture in said female jaw tail is positioned at an anglerelative to a line normal to the plane of said tail which isapproximately equal to one-half of the angle between said male andfemale jaw tails when said jaws are in said open position.
 14. In asolderless electrical connector according to claim 13, the improvementwherein said male jaw tail is slightly concave when said jaws are insaid open position and wherein said male jaw is sufficiently flexible topermit said male jaw tail to bend to a substantially planar positionwhen said male and female jaw tails are secured against said support.15. In a solderless electrical connector according to claim 13, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open position and wherein said male jaw is sufficientlyflexible to permit said male jaw tail to bend to a substantially planarposition when said male and female jaw tails are secured against saidsupport.
 16. In a solderless electrical connector of the rotatable jaw,clamping type comprising male and female jaws having respective mountingtails with alignable apertures therein adapted to receive a fastener andto be secured against a support, said male jaw including a transversecylindrical head joined to one end of said male jaw tail by a neck andhaving a bore which extends diametrically through the center of saidhead for receipt of a conductor, said female jaw including a C-shapedyoke joined to one end of said female jaw tail and defining a transversecylindrical socket which receives said head of said male jaw forrelative angular movement of said jaws between an open,conductor-receiving position and a closed, conductor-clamping position,said yoke having diametrically opposed cylindrical bores on a commondiameter of said yoke which are alignable with said bore in said malejaw in said open position of said jaws, the improvement wherein saidaperture in said female jaw tail is positioned at an angle relative to aline normal to the plane of said tail.
 17. In a solderless electricalconnector according to claim 16, the improvement wherein said male jawtail is slightly concave when said jaws are in said open positionwherein said male jaw is sufficiently flexible to permit said male jawtail to bend to a substantially planar position when said male andfemale jaw tails are secured against said support.
 18. In a solderlesselectrical connector of the rotatable jaw, damping type comprising maleand female jaws having respective mounting tails adapted to be securedagainst a support, said male jaW including a transverse cylindrical headjoined to one end of said male jaw tail by a neck and having a borewhich extends diametrically through the center of said head for receiptof a conductor, said female jaw including a C-shaped yoke joined to oneend of said female jaw tail and defining a transverse cylindrical socketwhich receives said head of said male jaw for relative angular movementof said jaws between an open, conductor-receiving position and a closed,conductor-clamping position, said yoke having diametrically opposedcylindrical bores on a common diameter of said yoke which are alignablewith said bore in said male jaw in said open position of said jaws, theimprovement wherein said male jaw tail is slightly concave when saidjaws are in said open position.
 19. In a solderless electrical connectoraccording to claim 18, the improvement wherein said male jaw issufficiently flexible to permit said male jaw tail to bend to asubstantially planar position when said male and female jaw tails aresecured against said support.